Dec 3 (Reuters) - Wall Street’s major indexes rallied on Monday following a trade truce between the United States and China, whose tensions have clouded the outlook for the stock market for much of the year.

The benchmark S&P 500 gained nearly 1 percent, building off of its biggest weekly percentage gain in nearly seven years a week ago, although the index had come off its earlier session highs in afternoon trading.

Investors were lifted by news over the weekend that U.S. President Donald Trump and Chinese President Xi Jinping agreed to hold off on new tariffs during talks in Argentina, declaring a truce following months of escalating tensions on trade and other issues.

“Today is mostly about celebrating the fact that the U.S. and China have delayed what could have been the some of the worst-case scenarios regarding their trade relations,” said Michael Arone, chief investment strategist at State Street Global Advisors.

Still, Arone noted that “there are still some very sticky issues that need to be resolved” between the world’s two biggest economies.

“We still have a long way to go to have what is an agreed-upon trading relationship between the U.S. and China, so I think that is a little bit of the pullback from the highs of the day as that settles in with investors,” Arone said.

The Dow Jones Industrial Average rose 232.91 points, or 0.91 percent, to 25,771.37, the S&P 500 gained 23.68 points, or 0.86 percent, to 2,783.85 and the Nasdaq Composite added 86.92 points, or 1.19 percent, to 7,417.46.

Last week, the S&P 500 gained 4.8 percent, rebounding after confirming its second 10 percent correction of the year, as investors interpreted commentary from the Federal Reserve as signaling that U.S. interest rate hikes may be less aggressive than feared.

On Monday, the technology sector, among the groups seen as sensitive to trade tensions, gained 1.7 percent. Apple shares, recently hit by worries over possible tariffs on iPhones, gained 2.3 percent.

Shares of Boeing and Caterpillar, two industrial companies viewed as trade bellwethers, gained 3.5 percent and 2.3 percent, respectively, and gave a lift to the blue-chip Dow. The industrial sector rose 1.2 percent.

Energy shares rose 2.0 percent as oil prices bounced back from their recent swoon. Along with the U.S.-China trade detente, oil got support as Canada’s Alberta province ordered a production cut, while exporter group OPEC looked set to reduce supply.

In corporate news, shares of Tesaro soared 58.7 percent after GlaxoSmithKline agreed to buy the U.S. cancer specialist for $5.1 billion.

Advancing issues outnumbered declining ones on the NYSE by a 2.38-to-1 ratio; on Nasdaq, a 1.48-to-1 ratio favored advancers.

The S&P 500 posted 38 new 52-week highs and no new lows; the Nasdaq Composite recorded 68 new highs and 61 new lows. (Additional reporting by Shreyashi Sanyal in Bengaluru; Editing by Shounak Dasgupta and Jonathan Oatis)